Symmetric Encryption Algorithms

Feistel Encryption

A symmetric structure used in the construction of block ciphers, named after Horst Feistel. It divides the plaintext block into two halves and processes them through multiple rounds of substitution and permutation.

SHA-1 (Secure Hash Algorithm 1)

A cryptographic hash function that produces a 160-bit (20-byte) hash value. It was widely used for digital signatures and certificates but is now considered insecure due to collision attacks.

Triple DES (3DES)

An enhancement of DES that applies the DES cipher three times with either two or three different keys, increasing security. Still used in some legacy systems.

AES (Advanced Encryption Standard)

A symmetric-key block cipher selected by NIST as a replacement for DES. Supports key sizes of 128, 192, and 256 bits and operates on 128-bit blocks. Widely used today.

Blowfish

A symmetric-key block cipher designed by Bruce Schneier. Operates on 64-bit blocks and supports variable-length keys up to 448 bits. Known for its speed and flexibility.

RC4 (Rivest Cipher 4)

A fast and simple stream cipher designed by Ron Rivest. Used in protocols like SSL and WEP, but now considered insecure due to several vulnerabilities.It uses a variable-length key up to 256 bits and is known for its simplicity in implementation, though its security flaws led to the decline in its usage.

IDEA (International Data Encryption Algorithm)

A symmetric-key block cipher with a 128-bit key and 64-bit block size. Designed to replace DES and used in PGP encryption. Considered secure but less commonly used today.It employs a series of operations that include modular addition, multiplication, and XOR, making it resilient against cryptanalysis.

Serpent

A symmetric-key block cipher that was a finalist in the AES competition. Uses 128-bit blocks and key sizes up to 256 bits. Known for high security and slower performance.

Camellia

A symmetric-key block cipher developed jointly by NTT and Mitsubishi. Supports 128-bit blocks and key sizes of 128, 192, and 256 bits. Used in TLS and IPsec.It is designed for efficiency and security, offering high performance on both hardware and software platforms while being resistant to various cryptanalytic attacks.

CAST5 (also know as CAST-128

A symmetric-key block cipher part of the CAST family. Uses 64-bit blocks and key sizes up to 128 bits. Used in OpenPGP and other applications.

Skipjack

A symmetric-key block cipher developed by the NSA for the Clipper chip. Uses an 80-bit key and 64-bit blocks. Classified until 1998; now obsolete. It supports up to 40 64-bit blocks and is primarily known for its use in government communications.

RC5

A parameterized block cipher designed by Ron Rivest, allowing variable block sizes, key sizes, and number of rounds. Flexible but not widely adopted.It supports block sizes of 32, 64, or 128 bits and can use key sizes of up to 2048 bits, making it adaptable for various applications.

RC6

An evolution of RC5, submitted to the AES competition. Features integer multiplication for improved performance. Not selected as AES.It is a symmetric-key block cipher with a block size of 128 bits and supports key sizes of 128, 192, and 256 bits.

GOST

A Soviet and later Russian symmetric block cipher standard. Uses 64-bit blocks and 256-bit keys. Part of the GOST standards suite; variants exist with different S-boxes.

Kuznyechik

The current Russian GOST standard symmetric block cipher. Uses 128-bit blocks and a 256-bit key. Adopted in 2015 as part of the new Russian encryption standard. It is also known as GOST R 34.11-2012 and replaces the earlier GOST block ciphers, offering improved security and efficiency.

ARIA

A South Korean symmetric-key block cipher standardized by KISA. Uses 128-bit blocks and supports 128, 192, or 256-bit keys. Used in government and commercial applications.

Safer (Secure And Fast Encryption Routine

A family of block ciphers designed by James Massey. Includes versions like SAFER K and SAFER SK. Used in early Bluetooth encryption.

ChaCha20

A stream cipher designed by Daniel J. Bernstein as a successor to Salsa20. Uses a 256-bit key and a 64-bit nonce. Known for high performance and resistance to timing attacks. Used in TLS and modern protocols.